source: trunk/ncurses/Ada95/samples/sample-explanation.adb@ 2787

Last change on this file since 2787 was 2621, checked in by bird, 19 years ago

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1------------------------------------------------------------------------------
2-- --
3-- GNAT ncurses Binding Samples --
4-- --
5-- Sample.Explanation --
6-- --
7-- B O D Y --
8-- --
9------------------------------------------------------------------------------
10-- Copyright (c) 1998,2004 Free Software Foundation, Inc. --
11-- --
12-- Permission is hereby granted, free of charge, to any person obtaining a --
13-- copy of this software and associated documentation files (the --
14-- "Software"), to deal in the Software without restriction, including --
15-- without limitation the rights to use, copy, modify, merge, publish, --
16-- distribute, distribute with modifications, sublicense, and/or sell --
17-- copies of the Software, and to permit persons to whom the Software is --
18-- furnished to do so, subject to the following conditions: --
19-- --
20-- The above copyright notice and this permission notice shall be included --
21-- in all copies or substantial portions of the Software. --
22-- --
23-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS --
24-- OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF --
25-- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. --
26-- IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, --
27-- DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR --
28-- OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR --
29-- THE USE OR OTHER DEALINGS IN THE SOFTWARE. --
30-- --
31-- Except as contained in this notice, the name(s) of the above copyright --
32-- holders shall not be used in advertising or otherwise to promote the --
33-- sale, use or other dealings in this Software without prior written --
34-- authorization. --
35------------------------------------------------------------------------------
36-- Author: Juergen Pfeifer, 1996
37-- Version Control
38-- $Revision: 1.18 $
39-- $Date: 2004/08/21 21:37:00 $
40-- Binding Version 01.00
41------------------------------------------------------------------------------
42-- Poor mans help system. This scans a sequential file for key lines and
43-- then reads the lines up to the next key. Those lines are presented in
44-- a window as help or explanation.
45--
46with Ada.Text_IO; use Ada.Text_IO;
47with Ada.Unchecked_Deallocation;
48with Terminal_Interface.Curses; use Terminal_Interface.Curses;
49with Terminal_Interface.Curses.Panels; use Terminal_Interface.Curses.Panels;
50
51with Sample.Keyboard_Handler; use Sample.Keyboard_Handler;
52with Sample.Manifest; use Sample.Manifest;
53with Sample.Function_Key_Setting; use Sample.Function_Key_Setting;
54with Sample.Helpers; use Sample.Helpers;
55
56package body Sample.Explanation is
57
58 Help_Keys : constant String := "HELPKEYS";
59 In_Help : constant String := "INHELP";
60
61 File_Name : constant String := "explain.msg";
62 F : File_Type;
63
64 type Help_Line;
65 type Help_Line_Access is access Help_Line;
66 pragma Controlled (Help_Line_Access);
67 type String_Access is access String;
68 pragma Controlled (String_Access);
69
70 type Help_Line is
71 record
72 Prev, Next : Help_Line_Access;
73 Line : String_Access;
74 end record;
75
76 procedure Explain (Key : in String;
77 Win : in Window);
78
79 procedure Release_String is
80 new Ada.Unchecked_Deallocation (String,
81 String_Access);
82 procedure Release_Help_Line is
83 new Ada.Unchecked_Deallocation (Help_Line,
84 Help_Line_Access);
85
86 function Search (Key : String) return Help_Line_Access;
87 procedure Release_Help (Root : in out Help_Line_Access);
88
89 procedure Explain (Key : in String)
90 is
91 begin
92 Explain (Key, Null_Window);
93 end Explain;
94
95 procedure Explain (Key : in String;
96 Win : in Window)
97 is
98 -- Retrieve the text associated with this key and display it in this
99 -- window. If no window argument is passed, the routine will create
100 -- a temporary window and use it.
101
102 function Filter_Key return Real_Key_Code;
103 procedure Unknown_Key;
104 procedure Redo;
105 procedure To_Window (C : in out Help_Line_Access;
106 More : in out Boolean);
107
108 Frame : Window := Null_Window;
109
110 W : Window := Win;
111 K : Real_Key_Code;
112 P : Panel;
113
114 Height : Line_Count;
115 Width : Column_Count;
116 Help : Help_Line_Access := Search (Key);
117 Current : Help_Line_Access;
118 Top_Line : Help_Line_Access;
119
120 Has_More : Boolean := True;
121
122 procedure Unknown_Key
123 is
124 begin
125 Add (W, "Help message with ID ");
126 Add (W, Key);
127 Add (W, " not found.");
128 Add (W, Character'Val (10));
129 Add (W, "Press the Function key labelled 'Quit' key to continue.");
130 end Unknown_Key;
131
132 procedure Redo
133 is
134 H : Help_Line_Access := Top_Line;
135 begin
136 if Top_Line /= null then
137 for L in 0 .. (Height - 1) loop
138 Add (W, L, 0, H.Line.all);
139 exit when H.Next = null;
140 H := H.Next;
141 end loop;
142 else
143 Unknown_Key;
144 end if;
145 end Redo;
146
147 function Filter_Key return Real_Key_Code
148 is
149 K : Real_Key_Code;
150 begin
151 loop
152 K := Get_Key (W);
153 if K in Special_Key_Code'Range then
154 case K is
155 when HELP_CODE =>
156 if not Find_Context (In_Help) then
157 Push_Environment (In_Help, False);
158 Explain (In_Help, W);
159 Pop_Environment;
160 Redo;
161 end if;
162 when EXPLAIN_CODE =>
163 if not Find_Context (Help_Keys) then
164 Push_Environment (Help_Keys, False);
165 Explain (Help_Keys, W);
166 Pop_Environment;
167 Redo;
168 end if;
169 when others => exit;
170 end case;
171 else
172 exit;
173 end if;
174 end loop;
175 return K;
176 end Filter_Key;
177
178 procedure To_Window (C : in out Help_Line_Access;
179 More : in out Boolean)
180 is
181 L : Line_Position := 0;
182 begin
183 loop
184 Add (W, L, 0, C.Line.all);
185 L := L + 1;
186 exit when C.Next = null or else L = Height;
187 C := C.Next;
188 end loop;
189 if C.Next /= null then
190 pragma Assert (L = Height);
191 More := True;
192 else
193 More := False;
194 end if;
195 end To_Window;
196
197 begin
198 if W = Null_Window then
199 Push_Environment ("HELP");
200 Default_Labels;
201 Frame := New_Window (Lines - 2, Columns, 0, 0);
202 if Has_Colors then
203 Set_Background (Win => Frame,
204 Ch => (Ch => ' ',
205 Color => Help_Color,
206 Attr => Normal_Video));
207 Set_Character_Attributes (Win => Frame,
208 Attr => Normal_Video,
209 Color => Help_Color);
210 Erase (Frame);
211 end if;
212 Box (Frame);
213 Set_Character_Attributes (Frame, (Reverse_Video => True,
214 others => False));
215 Add (Frame, Lines - 3, 2, "Cursor Up/Down scrolls");
216 Set_Character_Attributes (Frame); -- Back to default.
217 Window_Title (Frame, "Explanation");
218 W := Derived_Window (Frame, Lines - 4, Columns - 2, 1, 1);
219 Refresh_Without_Update (Frame);
220 Get_Size (W, Height, Width);
221 Set_Meta_Mode (W);
222 Set_KeyPad_Mode (W);
223 Allow_Scrolling (W, True);
224 Set_Echo_Mode (False);
225 P := Create (Frame);
226 Top (P);
227 Update_Panels;
228 else
229 Clear (W);
230 Refresh_Without_Update (W);
231 end if;
232
233 Current := Help; Top_Line := Help;
234
235 if null = Help then
236 Unknown_Key;
237 loop
238 K := Filter_Key;
239 exit when K = QUIT_CODE;
240 end loop;
241 else
242 To_Window (Current, Has_More);
243 if Has_More then
244 -- This means there are more lines available, so we have to go
245 -- into a scroll manager.
246 loop
247 K := Filter_Key;
248 if K in Special_Key_Code'Range then
249 case K is
250 when Key_Cursor_Down =>
251 if Current.Next /= null then
252 Move_Cursor (W, Height - 1, 0);
253 Scroll (W, 1);
254 Current := Current.Next;
255 Top_Line := Top_Line.Next;
256 Add (W, Current.Line.all);
257 end if;
258 when Key_Cursor_Up =>
259 if Top_Line.Prev /= null then
260 Move_Cursor (W, 0, 0);
261 Scroll (W, -1);
262 Top_Line := Top_Line.Prev;
263 Current := Current.Prev;
264 Add (W, Top_Line.Line.all);
265 end if;
266 when QUIT_CODE => exit;
267 when others => null;
268 end case;
269 end if;
270 end loop;
271 else
272 loop
273 K := Filter_Key;
274 exit when K = QUIT_CODE;
275 end loop;
276 end if;
277 end if;
278
279 Clear (W);
280
281 if Frame /= Null_Window then
282 Clear (Frame);
283 Delete (P);
284 Delete (W);
285 Delete (Frame);
286 Pop_Environment;
287 end if;
288
289 Update_Panels;
290 Update_Screen;
291
292 Release_Help (Help);
293
294 end Explain;
295
296 function Search (Key : String) return Help_Line_Access
297 is
298 Last : Natural;
299 Buffer : String (1 .. 256);
300 Root : Help_Line_Access := null;
301 Current : Help_Line_Access;
302 Tail : Help_Line_Access := null;
303
304 function Next_Line return Boolean;
305
306 function Next_Line return Boolean
307 is
308 H_End : constant String := "#END";
309 begin
310 Get_Line (F, Buffer, Last);
311 if Last = H_End'Length and then H_End = Buffer (1 .. Last) then
312 return False;
313 else
314 return True;
315 end if;
316 end Next_Line;
317 begin
318 Reset (F);
319 Outer :
320 loop
321 exit Outer when not Next_Line;
322 if Last = (1 + Key'Length) and then Key = Buffer (2 .. Last)
323 and then Buffer (1) = '#' then
324 loop
325 exit when not Next_Line;
326 exit when Buffer (1) = '#';
327 Current := new Help_Line'(null, null,
328 new String'(Buffer (1 .. Last)));
329 if Tail = null then
330 Release_Help (Root);
331 Root := Current;
332 else
333 Tail.Next := Current;
334 Current.Prev := Tail;
335 end if;
336 Tail := Current;
337 end loop;
338 exit Outer;
339 end if;
340 end loop Outer;
341 return Root;
342 end Search;
343
344 procedure Release_Help (Root : in out Help_Line_Access)
345 is
346 Next : Help_Line_Access;
347 begin
348 loop
349 exit when Root = null;
350 Next := Root.Next;
351 Release_String (Root.Line);
352 Release_Help_Line (Root);
353 Root := Next;
354 end loop;
355 end Release_Help;
356
357 procedure Explain_Context
358 is
359 begin
360 Explain (Context);
361 end Explain_Context;
362
363 procedure Notepad (Key : in String)
364 is
365 H : constant Help_Line_Access := Search (Key);
366 T : Help_Line_Access := H;
367 N : Line_Count := 1;
368 L : Line_Position := 0;
369 W : Window;
370 P : Panel;
371 begin
372 if H /= null then
373 loop
374 T := T.Next;
375 exit when T = null;
376 N := N + 1;
377 end loop;
378 W := New_Window (N + 2, Columns, Lines - N - 2, 0);
379 if Has_Colors then
380 Set_Background (Win => W,
381 Ch => (Ch => ' ',
382 Color => Notepad_Color,
383 Attr => Normal_Video));
384 Set_Character_Attributes (Win => W,
385 Attr => Normal_Video,
386 Color => Notepad_Color);
387 Erase (W);
388 end if;
389 Box (W);
390 Window_Title (W, "Notepad");
391 P := New_Panel (W);
392 T := H;
393 loop
394 Add (W, L + 1, 1, T.Line.all, Integer (Columns - 2));
395 L := L + 1;
396 T := T.Next;
397 exit when T = null;
398 end loop;
399 T := H;
400 Release_Help (T);
401 Refresh_Without_Update (W);
402 Notepad_To_Context (P);
403 end if;
404 end Notepad;
405
406begin
407 Open (F, In_File, File_Name);
408end Sample.Explanation;
409
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